Multi-character dropdown boxes

Does anyone have some ideas on how to put a multi-character dropdown box on
a form?

Example: If I'm in the combo (dropdown) box and type "BAC", I want it to
position to the first item that begins with "BAC". The default behavior is
to position to the first character beginning with B, then the first item
beginning with A, then to the first item beginning with C.

Thanks in advance.


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